One in ten hospitalised COVID-19 patients, who also have diabetes, may die within seven days of admission, and one in five may need to be intubated and mechanically ventilated by this point, according to a study.
Researchers, including those from the University of Nantes in France, analysed data from 1,317 COVID-19 patients admitted to 53 French hospitals between 10 and 31 March 2020.
They said a majority of the these patients, nearly 90 per cent, had type 2 diabetes, while only 3 per cent had type 1 diabetes, with other types of diabetes in the remaining cases.
According to the research, published in the journal Diabetologia, two thirds of the COVID-19 patients with diabetes admitted to the hospitals were men, and the average age of all patients was 70 years.
The researchers noted that bad blood sugar control did not directly seem to impact a patient's outcome, but the presence of diabetic complications and old age increased the risk of death.
They said an increased BMI, which is a measure of the weight of a person with respect to their height, is associated with both increased risk of needing mechanical ventilation, and with increased risk of death.
Complications were also noted in the eye, kidney, and nerves in 47 per cent of the subjects, while small blood vessel-related microvascular problems of the heart, brain, and legs were present in 41 per cent of the patients, the study noted.
Across all patients in this study, the researchers said, one in five had been intubated by day seven, and placed on a ventilator in intensive care.
By this time, they said about one in 10 had died, and a further 18 per cent had been discharged home. According to the researchers, microvascular complications more than doubled the risk of death at day seven.
They said advanced age also substantially increased the risk of death, with the group of patients aged 75 years more than 14 times likely to die than younger patients aged under 55 years.
Patients 65-74 years old were three times more likely to die than those under 55 years, the study noted.The scientists said the presence of the respiratory conditions like obstructive sleep apnoea, and symptoms like shortness of breath almost tripled the risk of death within a week.
"Elderly populations with long-term diabetes with advanced diabetic complications and/or treated obstructive sleep apnoea were particularly at risk of early death, and might require specific management to avoid infection with the novel coronavirus," the scientists wrote in the study.
The study also confirmed previous research that insulin, and other treatments for modifying blood sugar, are not a risk factor for severe forms of COVID-19 and can be continued in patients with diabetes.
According to the study, there were no deaths in patients under 65 years old with type 1 diabetes. However, the authors said there were only 39 patients with type 1 diabetes in the current study, adding that further research is needed to establish the effect of COVID-19 in this specific population.
Among other findings, the scientists said men were not statistically more likely to die at day seven than women. The researchers noted that BMI may also be an independent factor for COVID-19 severity in the population living with diabetes and requiring hospital admission.
"The link between obesity and COVID-19 requires further study," they said.